Sheet transfer between a turret punch press and an adjacent apparatus

ABSTRACT

A rotary turret, numerically controlled punch press is provided with a discharge station at 90° from a punching station. A part is clamped in the turret, separated from a larger workpiece and then rotated with the turret to the discharge station. A transfer arm having a part clamping mechanism is slaved to the NC punch press, engages the part at an exact attitude and position relative to a reference point on the part and transfers the part to a rotary chuck or part holder. The part is placed in the chuck at an exact attitude and with the reference point at the axis of rotation of the chuck.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 386,064, filed Aug. 6, 1973,which is a continuation-in-part of application Ser. No. 359,983, filedMay 14, 1973, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to sheet material handling and fabricatingmethods and systems and components of such systems. The sheet materialis of the self-shape-sustaining type, such as plastic, wood or metal.

2. Description of the Prior Art

In many industries, particularly the aerospace industry, there is a needfor the mechanized production of a relatively few irregularly shapedsheet material parts. For example, only two or three hundred such partsmay be needed in a year. Presently, these parts are made by firstcutting a templet and then, either by hand or with limited machinery,cutting the shape of the templet in the sheet material. After the partis cut, a considerable amount of manual deburring of the cut edge isrequired, with still more surface finishing following. The cost of suchindividual parts is quite high and, since a particular industry may needas many as two or three thousand different shaped parts manufactured inthis way, the ultimate cost is considerable.

There is, therefore, a need in the sheet material handling andfabricating industry for an apparatus or method to mechanize theproduction of a large variety of relatively few parts of sheet material.While the numerically controlled punch press is a useful tool forsatisfactorily fabricating holes or the like internally in the part, itis not satisfactory for cutting the peripheral shape of such irregularlyshaped parts, and thus cannot fully satisfy the need for fullmechanization.

One difficulty of automating apparatus for making parts is that theparts in the punch press have been removed manually such that thepositioning of the part in the subsequent automated machine must berepeated along with the additional programming of the machine.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an apparatus fortransferring a part from a turret punch press to a second machine whilemaintaining a high degree of accuracy in the location and angularattitude of the part in the second machine.

It is another object to provide an improved part transferring mechanism.

The term "automatic" used throughout this application means not onlyprogrammed control wherein the program is recorded on cards, tapes or ina larger general or special purpose computer, but the term also meansmanual remote control in which an operator is manually actuating thecontrols from a remote console. The invention is best utilized in thefully computerized automatic mode, however.

The objects of the invention are best obtained by a transfer mechanismthat, through predetermined, accurate arcuate and linear motions,engages the part at some predetermined location and attitude andpositions the part into a subsequent apparatus, such as, in thepreferred embodiment, the contouring apparatus of this application. Itis understood, however, that the accurate attitude and location controloffered by the transfer mechanism also makes the mechanism a usefuladdition to a turret-type punch press for other handling operations.

The transfer mechanism of the preferred embodiment includes an armpivotally mounted on a slider. The slider is provided with gauging meanswhich can be brought into abutment with a gauging surface on thenumerically controlled, workpiece positioning portion of the punchpress. In this manner, the position of a part engaging clamp on the arm,both as to attitude and location, is mechanically slaved to the punchpress relative to a reference point on the part. The part engaging clampcan be positioned along the arm, however, by an independent servo motor,if desired. The part is then swung by the transfer arm and, in thepreferred embodiment, the contouring apparatus is positioned to receivethe part in a correct angular attitude and with the reference pointlocated exactly in the center of a rotary chuck on the contouringapparatus.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a isometric of a punching and contouring apparatus embodyingthe principles of the invention.

FIGS. 2-7 are schematic, plan, operational views illustrating a sequenceof operation of the apparatus shown in FIG. 1.

FIG. 8 is a fragmentary horizontal section of a portion of the punchpress shown in FIG. 1 illustrating the separation of a part from alarger workpiece.

FIG. 9 is a fragmentary isometric of the transfer mechanism used in theapparatus in FIG. 1.

FIG. 10 is a fragmentary vertical section taken along the line 10--10 ofFIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT General Description

As best illustrated in FIG. 1, the preferred punching and contouringapparatus employing various inventive features includes a rotaryturret-type, numerically controlled punch press 10, preferably of thetype illustrated in U.S. Pat. No. 3,717,061, the description of which isincorporated herein by reference thereto. Alternatively, conventionalpunch presses of the type having a rotary turret for holding amultiplicity of tools can also be adapted by those skilled in the art toembody the principles of the invention. The punch press 10 includes amultiple tool turret 12 having a plurality of standard tools and aspecial tool and clamping mechanism as will be described herein below.In addition, the punch press is provided with workpiece positioningmeans 14 that locates by numerical or other suitable control a worksheetW beneath a punching station at the turret. In the preferred form ofpunch press illustrated, the workpiece positioning means 14 includes aside table 16 that moves with the worksheet along the Y axis of thepunch press. As will be described in more detail below, the side tableis provided with a gauging block 18 that can be accurately located alongthe Y axis by the side table and serves to position a transfer mechanism20.

The transfer mechanism 20 is basically a pivotal arm type, such asgenerally illustrated in U.S. Pat. No. 3,815,403, the details of whichare incorporated by reference thereto. The transfer mechanism is adaptedto move along the Y axis and swing a part P between the punch press andthe contouring apparatus to position the part very accurately in thecontouring apparatus.

The contouring apparatus 22 is located adjacent the punch press 10 andincludes, in general, a rotary turret 24 movable between four stations.The turret includes four arms, each carrying a rotary chuck or partholder 26. The turret moves the rotary chuck first to a cuttingapparatus 28, thence to a deburring apparatus 30, and finally to adischarge station where the part is removed from the chuck by a secondtransfer mechanism 32 which can then deliver the part to a subsequentfabricating apparatus, such as a surface finishing machine or a foldingmachine 34.

PART SEPARATION FROM WORKSHEET

In this apparatus, a multiple number of parts can be removed from alarger worksheet while the worksheet remains in the punch press. Forthis purpose and as best shown in FIGS. 8 and 10, the turret 12 isprovided with a special tooling which includes a conventionalthin-section punch and die 36 suitable for cutting through the remainingpiece of material 37 connecting the part P-1 with worksheet W after thepart has been completely nibbled substantially free of the worksheetonly lines 38. The internal notches, openings, etc., necessary in thepart P-1 are made using conventional punch press procedures. Next, theedge 38 is nibbled on all sides connected to the worksheet W, leavingthe one connected portion 37 remaining. The turret 12 is then rotateduntil the tool 36 is positioned beneath the striker of the punch press.

On the turret 12, adjacent the special tool 36, are two or more (twoillustrated) clamps. Each clamp includes a pneumatically operated pistonrod 42 which can be thrust downwardly against the part holding itagainst a block 43. With the two clamps engaging the part, the punch 36can then be actuated, severing the last remaining connection with theworksheet. While still clamped, the part is then rotated 90° by theturret 12 to the side of the punch press to the part removal stationwhile the worksheet is withdrawn by the worksheet positioning means 14.At this time, the part separation is complete, with the part P-1 beingin a position laterally of the side of the punch press, where, uponraising clamp piston rods 42, it is easily accessible for removal. Afterremoval, the next part can be punched and the separation procedurerepeated.

TRANSFER MECHANISM

As is readily understood, the size of the parts P may vary for eachdifferent worksheet W and, if desired, may even vary within a singleworksheet. As a result, it is necessary in the preferred embodiment thatthe part P be positioned in the punch press 10, transfer mechanism 20and, ultimately, in the chuck 26 in a predetermined and accurate mannerso that programmed controls can be utilized. Since the final separationof the part from the worksheet always occurs at the same corner, theupper left-hand corner, as shown in FIG. 8, edge e of the part willalways be at the same distance from the outside of the turret 12,regardless of the size of the part.

The invention of this application provides a transfer mechanism that canengage the part always at a known location along the X axis of the punchpress. The dimension a of the part, however, may vary. This variance, aswill be seen, is uniquely provided for in the preferred embodiment byslaving the transfer mechanism to the NC controls of the punch press.Furthermore, in positioning the transfer mechanism relative to the part,it is also important to engage the part with reference to somepredetermined reference point O, which, as will be described, becomesthe center of rotation of the part in the part holder 26. Preferably,although not necessarily, the reference point O is at the approximategeometrical center of the part.

As best shown in FIGS. 1 and 9, the preferred transfer mechanism 20includes a transfer arm 45 pivotally mounted on a slider 43. The slideris slidably mounted on a rail 46 which forms a part of the punch press10. The movable side table 16 of the punch press also slides on the rail46, as more fully described in U.S. Pat. No. 3,717,061. The slider 43 isprovided with a gauge bar 47 which abuts against the gauge block 18 onthe movable side table. A pneumatic ram 48 slides the slider between afully retracted position, as shown in FIG. 9, and a fully extendedposition, as limited by the position of the gauge block 18. The arm isswung about its pivot by a second pneumatic ram 50 between two positionsat a 90° angle with each other, that is, either fully parallel or fullyperpendicular to the X axis of the punch press 10. Suitable details ofconstruction for the transfer mechanism 20 can be obtained from saidU.S. Pat. No. 3,815,403, including a suitable part clamp 52 forreleasably holding the part.

In operation, the input of the computer or other control for thepunching and contouring apparatus will receive the information as to thedimensions of the outer periphery of the part, namely dimensions a andb, as shown in FIG. 8, and the locating data for reference point O.After the part has been rotated 90° to its discharge position, thedimension a will be used to position the clamp 52 of the transfermechanism. Although there are various techniques for moving the sidetable 16 and the slider 43, the preferred operation is to first returnthe side table 16 to the left to its home position along the Y axis ofthe machine. As the distance between the end of gauge bar 47 and thecenter of the clamp 52 is known, the exact position of the clamp 52along the Y axis when the gauge bar 47 is abutting the block 18 is alsoknown. It is thus a simple calculation to determine the distance thatthe side table must move from its home position in the Y axis toposition the center of the clamp 52 at the reference point O along thedimension a of the part P-1. Thus, if the dimension a is 15 inches andthe reference point O is 71/2 inches in from the left-hand edge of thepart P-1, along dimension a the side table will advance along the Y axis71/2 inches, assuming the center of clamp 52 is aligned with edge f ofthe part when the side table is in the home position, to position thecenter of the clamp 52 along the imaginary line passing throughreference point O.

As is also best apparent from FIG. 2 of the drawing, the center of theclamp 52, when arm 45 is swung away from the punch press, is also alongan imaginary line which passes through the center of the chuck 26 sothat by merely swinging the part through a 90° arc, the reference pointO is in perfect alignment with the center of the chuck 26. Then, toposition the reference point O centrally in the chuck along thedimension b of the part, it is only necessary to move the chuck on thecontouring apparatus toward or away from the transfer mechanism 20 thecorrect distance in a manner similar to the initial positioning of thepart in the clamp 52. That is, input known dimension b to the controlfor the punching and contouring apparatus will provide the necessarydistance that the chuck 26 must be moved toward or away from the clamp52 so that the chuck will center itself over the reference point O onthe part P-1.

While the preferred embodiment employs a mechanical interconnection toslave the position of clamp 52 relative to the part along the Y axis, itshould also be understood that rather than have the arm slide on guide46, the clamp 52 could be mounted to slide on arm 45, powered by a servomotor to accurately align the clamp by numerical control. Furthermore,various other combinations of arm movement can be utilized, such as, bymoving first along the X axis to grab the edge opposite edge f and thenlinearly reciprocating the part along the X axis, plus rotating the armto place the part in the part holder 26.

CONTOURING APPARATUS

The contouring apparatus 22 is best shown in FIGS. 1 and 2. Theapparatus comprises a base 52 on which is mounted a movable carriage 54.The carriage 54 slides on rails 56 in a direction parallel to the Y axisof the punch press. It should be understood at this point that themoveable direction of the carriage 54 need not be parallel to the Y axisof the punch press, but rather, can be any direction which avoidsinterference with operation of the punch press. The carriage is moved bya conventional worm drive powered by a motor 58. The turret 24 isrotatably mounted on the movable carriage 54 and includes a spider orset of upper arms which can be rotated as shown. The rotary chucks orpart holders 26 are positioned at the ends of the arms. Further detailsof the turret 24 may be obtained from application Ser. No. 386,064. Itis, of course, apparent that the turret can be linearly reciprocated androtated and the chucks or part holders rotated to establish a desiredorientation of the parts.

OVERALL OPERATION OF APPARATUS

Reviewing the operation, it can be seen that a large worksheet W isplaced in the punch press 10 in FIG. 2. At this time, it is assumed thatthe contouring apparatus 22 is empty. In FIG. 3, a part has been punchedwith its desired internal hole configuration and the turret 12 moved tothe special tooling and clamping station. At this time, the piston rods42 are actuated to hold the part independently of the worksheetpositioning means 14. Next, the final punch 36 removes the lastconnecting piece of material 37, freeing the part P-1 from the worksheetW. In FIG. 4, the side table 16 is moved to the right from the homeposition a sufficient distance to allow the gauge 42 to abut against thegauge block 18 and locate the clamp 52 of the transfer mechanismcentrally in alignment with the reference point O in the part P-1. InFIG. 5, the part P-1 is moved along the y axis and rotated away from thepunch press into a part delivery station. At this point, the part hasbeen completely removed from the punch press, ready to be placed in acontouring apparatus.

In FIG. 6, the arm 45 remains in its home position, to the right in FIG.6, while the movable carriage 54 is positioned so that the central axisof the rotary chuck 26 is directly aligned with the reference point O onthe part P-1. In FIG. 7, the turret 24 now holds the part. As shown inphantom lines, it can be seen that the part P-1 is simultaneouslyrotated as it is moved from the receiving position to the cuttingstation and retains its same angular orientation between the stations.In FIG. 8, the movable carriage 54 is moved toward the cutting apparatus28 and the part P-1 is rotated with the afore-described simultaneousmotions of the part and blade attitude to begin to cut a peripheralshape on the part P-1.

While the preferred embodiments of the invention and various inventivefeatures of the invention have been illustrated and described, it shouldbe understood that modifications and variations to each of them will beapparent to one skilled in the art without departing from the principlesherein.

The embodiments of the invention in which a particular property orprivilege is claimed are defined as follows:
 1. A transfer mechanism foraccurately removing a sheet material part from a punch press, of thetype having a plurality of tools with the worksheet movable beneath saidtools in X and Y horizontal mutually perpendicular axes and worksheetpositioning means for moving a worksheet along the X and Y axes, and forpositioning the part accurately in a part holder of an adjacentapparatus, comprising arm means having a part clamping member at oneend, said part clamping member including means for directly engaging thesheet material part, support means pivotally mounting said arm means,powered means for positioning the part clamping member in a firstdirection relative to the part and along the Y axis a distance in directcorrelation with the location of the punch press worksheet positioningmeans in the same Y axis, means for rotating the arm after clamping thepart to align the clamping member with said part holder, means forlinearly translating the part holder of the adjacent apparatus towardand away from said part clamping member when said clamping member isrotated from said punch press to position the part in a second directionin the part holder, and control means for so positioning the part holderrelative to said clamping member in the second direction according tothe dimension of the part in the second direction to exactly positionthe part in the part holder in a desired orientation and location. 2.The apparatus of claim 1, said punch press including guide meanspositioned along the Y axis of the punch press, said arm support meansbeing slidably mounted on said guide means, said powered means slidablymounted on said guide means, said powered means slidably moving thesupport means on said guide means for moving the part clamping memberalong the Y axis, and gauge means on said arm for contacting saidworksheet positioning means of the punch press for positioning the partclamping member according to the dimension of the part in the Y axis. 3.The apparatus of claim 2, said part having known right angle referenceaxes intersecting at a reference point, program means for recording thelocation of said reference point, said program means being operativelycoupled to said control means for locating the reference axes and pointof the part exactly in a predetermined position and orientation in saidpart holder.
 4. The apparatus of claim 2, said worksheet positioningmeans including a side table movable from a home position, a stopsurface on said table for providing a known distance from the table homeposition, said gauge means including a gauge bar secured to said armsupport means and movable into engagement with said stop surface forpositioning said part clamping member relative to said stop surface,said worksheet positioning means including means for moving the sidetable a known distance along the Y axis dependent upon the dimension ofthe part in the Y axis.
 5. The apparatus of claim 4, said side tablebeing movable along the Y axis of the punch press also on said guidemeans.
 6. A transfer mechanism for accurately removing a sheet materialpart from a part removal station of a punch press, of the type having aturret carrying a plurality of tools and numerically controlledworksheet positioning means for moving a worksheet along first andsecond perpendicular mutually horizontal axes, and for positioning thepart accurately in a part holder of an adjacent apparatus at a partdelivery station offset along both said horizontal axes from saidremoved station, comprising part clamping means for directly graspingsaid part, means for moving said part clamping means along said firsthorizontal axis and adapted to be in a first direction relative to saidpart for directly grasping the sheet material part while in said punchpress at a variable location along said first horizontal axis and firstdirection and for placing said part at said delivery station in saidpart holder accurately positioned relative to said part holder in saidfirst direction relative to said part so that the part can be operatedon by said adjacent apparatus starting from a predetermined location andorientation of said part in said part holder.
 7. The transfer mechanismof claim 6, said means for moving said part clamping means including armmeans for carrying said part clamping means, means for pivotallysupporting said arm means, first powered means for moving said partclamping means along said first horizontal axis, and second poweredmeans for rotating said arm means to said part delivery station at saidadjacent apparatus.
 8. The transfer mechanism of claim 7, includingpowered means for positioning said part holder also along said firsthorizontal axis when said arm means is rotated 90° from said partremoval station for locating the part in a second direction relative tosaid part in said part holder.
 9. The transfer mechanism of claim 6,including means for controlling movement of said part clamping meansdirectly dependent upon the position of said numerically controlledworksheet positioning means whereby the location of said part clampingmeans is determined by the locating of said worksheet positioning meansof said punch press.
 10. A transfer mechanism for removing a flatworksheet of variable dimensions from a punch press, of the type havinga turret carrying a plurality of tools and numerically controlledworksheet positioning means for moving a worksheet along first andsecond mutually perpendicular horizontal axes relative to the turret,and subsequently accurately and automatically positioning the punchedworksheet in a part holder of an adjacent apparatus,comprising:worksheet clamping means for directly grasping the worksheetwhile on said punch press, means for moving said worksheet clampingmeans in two directions for locating said clamping means on saidworksheet and locating said worksheet in said part holder, and controlmeans for positioning the worksheet clamping means in one directionrelative to said worksheet and at a desired location along one sidehorizontal axis, said control means including stop means movable indirect relation with said clamping. means and engageable with saidnumerically controlled worksheet positioning means of said punch pressfor locating said stop means along said one horizontal axis and thussaid clamping means at a known distance along said worksheet in directrelation to a numerically controlled movement of said punch pressworksheet positioning means whereby the worksheet clamping means ismoved by an independent moving means but is located by said numericallycontrolled worksheet positioning means.
 11. The apparatus of claim 10,said means for moving said worksheet clamping means including arm meanspivotally mounted on a movable support and means for reciprocating saidmovable support toward and away from said worksheet positioning means ofsaid punch press, said worksheet clamping means being secured to saidarm means remote from said support, said stop means including a gaugebar fixed to said support, said worksheet positioning means including agauge surface engageable by said gauge bar.
 12. The apparatus of claim10, said means for moving said worksheet clamping means includingpivotally mounted arm means.